Process for the in-situ production of a sorbent-oxide aerosol used for removing effluents from a gaseous combustion stream

Abstract

A process for the in-situ production of an effluent sorbent-oxide aerosol during the combustion of a hydrocarbon containing fuel whereby the effluents are removed from the resultant gaseous hydrocarbon stream comprises admixing an aqueous solution of the sorbent with the fuel, atomizing and combusting the mixture under controlled conditions so as to generate the effluent sorbent-oxide aerosol.

What is claimed is: 
     
       1. A process for the in-situ production of an effluent sorbent-oxide aerosol during the combustion of a hydrocarbon containing fuel whereby effluents are removed from the resultant gaseous hydrocarbon combustion stream, comprising the steps of: (1) forming an aqueous solution comprising an effluent sorbent compound selected from the group consisting of CaCl 2 , Ca(CH 3  COO) 2 , Ca(CHOO) 2 , Ca(OH) 2  and mixtures thereof dissolved in water; (2) admixing the aqueous solution of the effluent sorbent with a hydrocarbon containing fuel so as to form a combustible fuel mixture; (3) atomizing said combustible fuel mixture and feeding said atomized fuel mixture to a combustion zone; (4) combusting said atomized fuel mixture in said combustion zone under controlled temperature conditions T 1  wherein T 1  is between about 1900° K. to about 2200° K. in the presence of an oxygen containing oxidant so as to obtain a sorbent-oxide aerosol comprising ultra-fine sorbent-oxide particles having a mean diameter of submicron size in said gaseous combustion stream; (5) partially cooling said combustion stream to a temperature T 3  of between about 1400° K. to 1600° K. downstream of the combustion zone; (6) feeding additional oxidant to said partially cooled gaseous stream downstream of the combustion zone at temperature T 3  wherein oxygen is present in greater than the stoichiometric ratio with said hydrocarbon fuel and wherein between about 60 to 95% of the total oxidant is fed to the combustion zone and between about 5 to 40% of the total oxidant is fed to said partially cooled gaseous stream; and (7) further cooling said gaseous combustion stream downstream of said combustion zone to a temperature T 2  wherein T 2  is between about 700° K. to about 1350° K. so that said sorbent-oxide particles absorb said effluents from said gaseous combustion stream. 
     
     
       2. A process according to claim 1 wherein said temperature T 2  is between about 1000° K. to about 1350° K. 
     
     
       3. A process according to claim 1 wherein said sorbent-oxide particles have a mean diameter of about ≦0.5 μm. 
     
     
       4. A process according to claim 1 wherein said fuel mixture is atomized by an atomizing fluid. 
     
     
       5. A process according to claim 1 wherein said hydrocarbon fuel contains sulfur which upon combustion forms a sulfurous by-product effluent in the form of SO x . 
     
     
       6. A process according to claim 5 wherein said fuel mixture has a Ca to S ratio of up to 2.5. 
     
     
       7. A process according to claim 5 wherein said fuel mixture has a Ca to S ratio of between about 0.6 to 1.2. 
     
     
       8. A process according to claim 6 wherein at least 35% by weight of said sorbent is utilized in sulfur absorptions so as to obtain a sulfur reduction in the amount of at least 21% when compared to sorbent-free combustion processes. 
     
     
       9. A process according to claim 8 wherein said sorbent utilization is greater than 50%. 
     
     
       10. A process according to claim 1, further including the step of admixing a sorbent solubility enhancing compound in said aqueous solution forming step. 
     
     
       11. A process according to claim 10 wherein said sorbent solubility enhancing compound is selected from the group consisting of sucrose, glycerol, alcohols and mixtures thereof. 
     
     
       12. A process for the in-situ production of an effluent sorbent-oxide aerosol during the combustion of a hydrocarbon containing fuel whereby effluents are removed from the resultant gaseous hydrocarbon combustion stream, comprising the steps of: (1) providing a hydrocarbon containing fuel; (2) forming an aqueous solution comprising an effluent sorbent compound selected from the group consisting of CaCl 2 , Ca(CH 3  COO) 2 , Ca(CHOO) 2 , Ca(OH) 2  and mixtures thereof dissolved in water; (3) separately feeding said hydrocarbon fuel and aqueous solution to a combustion zone wherein said fuel and solution are admixed: (4) combusting said fuel mixture in said combustion zone under controlled temperature conditions T 1  wherein T 1  is between about 1900° K. to about 2200° K. in the presence of an oxygen containing oxidant so as to obtain a sorbent-oxide aerosol comprising ultra-fine sorbent-oxide particles having a mean diameter of submicron size in said gaseous combustion stream; (5) partially cooling said combustion stream to a temperature T 3  of between about 1400° K. to 1600° K. downstream of the combustion zone; (6) feeding additional oxidant to said partially cooled gaseous stream downstream of the combustion zone at temperature T 3  wherein oxygen is present in greater than the stoichiometric ratio with said hydrocarbon fuel and wherein between about 60 to 95% of the total oxidant is fed to the combustion zone and between about 5 to 40% of the total oxidant is fed to said partially cooled gaseous stream; and (7) further cooling said gaseous combustion stream downstream of said combustion zone to a temperature T 2  wherein T 2  is between about 700% to about 1350% so that said sorbent-oxide particles absorb said effluents from said gaseous combustion stream.